There is currently a strong trend to replace conventional incandescent light bulbs with light bulbs based on SSL technology since these typically have superior performance with respect to energy efficiency, operational lifetime and many other factors. An example of such a light bulb is disclosed in WO 2014/080301 A1. This document discloses a lighting device that has light-emitting diodes (LEDs) mounted on small tabs of a sheet made of a heat-conducting material inside a housing.
Examples of the technical considerations that must be addressed when making a light bulb based on SSL technology include how to efficiently cool the SSL devices and how to achieve a light distribution that meets the requirements of the intended application. Further efforts aimed at finding innovative solutions to these technical challenges are warranted.
US 2014/0049972 discloses a cylinder-shaped lighting device in which the envelope comprises a flexible substrate provided with LEDs. The cylinder-shaped envelope is mounted on a base for establishing the electrical and mechanical connection with a socket.
WO 2013/078180 discloses a flexible substrate comprising LEDs for use in a lighting device, for instance in retrofit bulbs.